Carbon Flashcards
What is the biological pump?
- Sequestration of CO2 to oceans by phytoplankton
- Float on surface of oceans to access sunlight for photosynthesis
- Carbon transferred from atmosphere into phytoplankton
- Carbon passed up food chain by consumers where it is then released back into the atmosphere
- Most carbon is cycled in surface waters this way
- Only 0.1% of carbon reaches sea floor through decomposition and sedimentation
- Phytoplankton sequester over 2billion metric tonnes of CO2 annually to the deep ocean
What is the carbonate pump?
- Actively moves CO2 from atmosphere into the ocean store
- Ocean is usually at high temperature and low pressure
- Many marine organisms use calcium carbonate to build their outer shells/skeletons
- When these organisms die, they will sink to the sea floor and their shells will dissolve, dissolving the CO2 with it into the ocean
- The dissolved CO2 circulates around the planet in currents for up to 500 years
- Any shells that do not dissolve build up on the bottom of the sea floor, forming limestone
- Intermediate and deep ocean store around 37,100Gt
What is the physical pump?
- Based on global circulation of water
1. Moves carbon compounds to different parts of the ocean in downwelling and upwelling currents
2. Downwelling occurs in parts of the ocean where cold, denser water sinks (+ more salinity), such as the poles
3. These currents bring dissolved carbon dioxide down to the deep ocean.
4. Once there, it moves in slow-moving deep ocean currents, staying there for hundreds of years (around 500).
5. Eventually, these deep ocean currents, part of the thermohaline circulation, return to the surface by upwelling.
6. The cold deep ocean water warms as it rises towards the ocean surface and some of the dissolved carbon dioxide is released back into the atmosphere
7. CO2 concentration is 10% higher in the deep ocean that at the surface
How does ocean and terrestrial photosynthesis regulate composition of atmophere?
- Photosynthesis requires CO2 to occur
- Therefore, oceanic and terrestrial autotrophs absorb CO2 from the atmosphere so it enters the biosphere of the organism
- Here, the CO2 is either released back into the atmosphere, used in metabolic processes or becomes part of a consumers biomass if the organism is eaten and used to synthesis their biological molecules
How is soil health influenced by stored carbon?
- Soil health depends upon the the amount of carbon stored in the soil
- Carbon is the main component of soil organic matter and helps to give soil its moisture-retention capacity, its structure and fertility
- Organic carbon is concentrated in the surface layer of the soil
- A healthy soil has a large surface reservoir of available nutrients which, in their turn, condition the productivity of ecosystems
- All this explains why even a small amount of surface soil erosion can have such a devastating impact on soil health and fertility
What factors affect carbon sequestration in soils?
- Climate
- Soil type
- Management or use of soils
How does climate affect carbon sequestration into soils?
- Rapid decomposition occurs at higher temperatures or under water logged conditions
- Places with high rainfall or a hotter climate have an increased potential soil carbon store
- Arid soils can only store 30tonnes per hectare compared with 800 tonnes per hectare in cold regions
How does management and use of soils affected carbon sequestration?
- Since 1950 soils have lost 40-90billion gigatons of carbon through cultivation and disturbance
- Current rates of carbon loss due to land use change are 1.6billion gigatons of carbon per year
How does soil type affect carbon sequestration?
-Clay rich soils have a higher carbon content than sandy soils as clay protects carbon from decomposition
What is energy security?
Being able to access reliable and affordable energy sources, either domestic or from ‘friendly’ overseas countries
Urban energy consumption:
- Over half of the world’s population now live in cities
- They consume 75% of world’s energy and produce 80% of its GHGs
- London generates 1.7million tonnes of carbon per year, which is 1.8tonnes per capita
Rural energy consumption:
- In rural Peru, a national programme was launches where electricity was made available to 500,000 people in villages between 2006 and 2015 through the use of solar panels
- This allowed people to charge phones, power lights and TVS as well as extend the working day
- Increased productivity has allowed extra processing of cereals, meats, cocoa and wood
- This has boosted incomes and raise rural living standards
Why does energy consumption differ between countries?
- Physical availability
- Technology
- Cost
- Economic development
- Environmental priorities
How does physical availability affect energy consumption?
- Imported energy requires transport which adds onto the overall cost for the consumer
- Rising costs are likely to decrease consumption
- Domestic energy can be difficult to access and requires expensive technology
How does climate affect energy consumption?
- Very high levels of consumption in North America, Middle East and Australia reflect the extra energy needed to make extremes of hot and cold more comfortable
- Compared to places like France that have a more temperate climate, less energy needs to be consumed for technology such as AC and Central Heating year round
- Dubai, Middle East summer temperatures reach around 40*C but are still hot year round
How does cost affect energy consumption?
- Cost includes physical exploitation, processing and delivery to consumer
- Relatively low energy costs many be expected to boost consumption
How does economic development affect energy consumption?
- Same energy cost may be perceived as expensive in one country and acceptable in another
- Public perception will depend very much on the level of economic development and standard of living
- The higher these are, the less sensitivity to energy cost
- Developed countries, therefore, have relatively high levels of energy consumption
- Energy needs to fuel domestic appliances, transport, etc.
- Also if country, notably China, is going through rapid economic development then energy consumption is going to be high for a period of time in order to keep up with demand
How do environmental priorities affect energy consumption?
- Out of concern for environment in general and about carbon emissions in particular a government may not take a cheapest route to meets its energy needs
- Wind turbines, solar panels and other renewables can be more expensive, especially due to their lower efficiency
- Therefore the cost of green energy could have a slightly depressing impact on consumption
Energy Consumption Case Study: USA vs France
- USA’s energy consumption almost 10 times higher than France’s
- USA is at 2224mtoe compared to 243mtoe for France
- USA’s energy consumption is 3000kge higher than France’s
- Only 50% of France’s energy comes from fossil fuels compared to 80% for the USA
- Only 10% of USA’s energy comes from renewables and 8% from nuclear
- In comparison, 10% of France’s energy comes from renewables and 40% from nuclear
- France’s population is 66.9million (2018) compared to the USA’s population of 327.2million (2018)
Why does France have a lower energy consumption than the USA?
- Much smaller population
- Less major cities to power
- USA has higher GDP per capita
- USA experiences extreme heat and cold
What is energy mix?
Proportion of each primary resources a country uses per year. These resources may be domestic or imported
What is the UK’s energy mix?
Coal and Oil: 1% Natural Gas: 38% Wind: 20% Biomass: 12% Solar: 6% Nuclear: 19%
What factors affect energy mix?
- Geopolitical links e.g. Gazprom
- Financial cost of each energy option
- National and regional policies on climate change e.g. Paris Climate Change Agreement 2015, UK National Policy to band diesel cars by 2035
- Energy needs based on economic development and lifestyle e.g. USA has high demand so uses fossil fuels. On other hand, USA has funds to invest into efficient renewable technology
- Availability of primary resources within the country, as well as their access to technology to extract the resources e.g. Russia exports 80% of its natural gas to Europe
Norway Energy Security Case Study:
- Norway is very energy secure
- Norsk Hydro runs over 600HEP sites, which supplies 97.5% of Norway’s renewable electricity
- Because Norway is mountainous with steep valleys and plentiful rainfall, HEP is the natural energy choice
- Much of the oil and natural gas in Norway’s natural waters is exported
- HEP costs are low once capital investment is complete
- However, transfer of electricity from HEP stations in remote regions to urban populations and isolated settlements is expensive
- Norwegian government prevents foreign companies from owning any primary energy source sites, so they are energy secure for the future and have the potential to become a major exporter
- Norway is the third largest exporter of hydrocarbons
- In 2015, Norway committed to a 40% reduction in domestic GHG emissions by 2030
UK Energy Security Case Study:
- Not very energy secure
- Was one of the leading countries in energy in the 1950s to 70s
- UK heavily depended on coal from Yorkshire, Derbyshire and Nottinghamshire
- It was also among global leaders in nuclear technology
- North Sea reserves became a ‘secure’ alternative to dependency on Middle Eastern oil
- North Sea oil is expensive to extract so if global prices fall it becomes less viable
- Stocks of North Sea oil and gas are declining which is forcing the UK to import more
- 150 years worth of coal reserves left in UK but current technology and environmental policy makes its extraction unrealistic and expensive
- Technology exists for ‘clean’ coal (absorbing CO2) but coal has lost is political support
- Privatisation of UK’s energy supply industry in the 1980s means overseas countries decide which energy sources are used to meet UK demand, they buy primary energy on international markets
- Increase in nuclear technology and renewables
OPEC as an energy player:
- Organisation of the Petroleum Exporting Countries
- Made up of 12 member countries in which own 2/3s of world’s oil reserves between them
- OPEC in a position to control amount of oil and gas entering the global market
- Also able to set prices of both commodities
- Been accused of holding back production in order to drive up oil prices